In order to install railworks content, you have two do two things. First of all, you have to go into your graphics card's settings and disable dynamic antialiasing. If you don't disable it, your trucks will be see through. Next, in order to get third party content to get through, you have to disable a DRM file called Win32. Just search your computer for it, and delete it.
Does anyone else hate how companies like the RW company put DRMs in their software to prevent piracy even though they are on steam. It is so stupid.